Submission #338443

#	Time	Username	Problem	Language	Result	Execution time	Memory
338443		BY_KUTBILIM	Chessboard (IZhO18_chessboard)	C++14	70 / 100	260 ms	2156 KiB

chessboard

/** @BY_KUTBILIM **/
#include <bits/stdc++.h>
using namespace std;

#define ff first
#define ss second
#define pb push_back
#define ll long long
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).end()

const int inf = (int)1e9+7;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie();

    int k;
    ll n;
    cin >> n >> k;
    int x1[k], x2[k], y1[k], y2[k];
    vector<ll> div;
    div.pb(1);
    for(int i = 2; i <= sqrt(n); i++){
        if(n % i == 0){
            div.pb(i);
            if(i != n / i){
                div.pb(n/i);
            }
        }
    }
    sort(all(div));
    vector<ll> cnt1((int)div.size(), 0), cnt0((int)div.size(), 0);
    for(int i = 0; i < k; i++){
        cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
        x1[i]--;
        y1[i]--;
        for(int j = 0; j < (int)div.size(); j++){
            if((x1[i] / div[j] + y1[i] / div[j]) % 2 == 0)cnt0[j]++;
            else cnt1[j]++;
        }
    }
    ll ans = n * n;
    for(int i = 0; i < (int)div.size(); i++){
        ans = min({ans,
        n * n / (div[i] * div[i]) / 2ll * (div[i] * div[i]) + (div[i] * div[i]) - cnt0[i] + cnt1[i],
        n * n / (div[i] * div[i]) / 2ll * (div[i] * div[i]) - cnt1[i] + cnt0[i]});
    }
    cout << ans;

    return 0;
}
/*

6 8
3 3 3 3
1 2 1 2
3 4 3 4
5 5 5 5
4 3 4 3
4 4 4 4
2 1 2 1
3 6 3 6

*/

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 23 / 23
• Subtask 6: 0 / 30